Excellent article. I’m currently reading ’12 Rules’ and am certainly enjoying the metaphors. I think the point where he and Harris get stuck is that Harris argues that these metaphors can be said of virtually anything. There is an instance where Harris makes the same “Petersonian” claims of a cook book on a book shelf. In other words, from Harris’ POV, it’s merely ad hoc labeling. I don’t know and I don’t care. I think there is a hunger to find meaning in things.
As for the Buddhist label, I could have sworn Harris DID label himself a Buddhist but that was many years ago. The thing is, mindfulness and and contemplative experiences are universal and can be found in many traditions. Also, Buddhist tradition does carry with it some metaphysical claims (though these are ancillary, and not central to the religion), so depending on how one defines Buddhism, perhaps he isn’t one.